Operating Restrictions - Sharp LM161 Series User Manual

OPERATING RESTRICTIONS

The LSI (HD44780AXX) used in the LCD units is
reported to have the following defects:
HD44780AXX Defective Functions
1. When the display clear or display/cursor home
instruction is executed when the display has
been shifted from its original position, original
display position may not be restored.
2. When the display/cursor home instruction is
executed, the data in the following display data
RAM locations may be lost.
A. Address type a.
Address HEX 00 01 02 03 04 05 06 07
B. Address type b and c.
Address HEX
00 01 02 03 04 05 06 07
Address HEX
40 41 42 43 44 45 46 47
NOTE: Although address type C is for a single-line display its
address structure is logically the same as for address type b.
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Display Unit User's Manual
To counteract these defects. The following re-
strictions should be followed (Table 16).
In the production facility, the LSI device in ques-
tion is now being replaced with a modified version,
HD44780RAXX. The above mentioned restrictions
do not apply to products using the "RA" version of
the LSI. The "RA" version devices have an "R"
printed in the upper, right corner, as shown.
. . . . . .
41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F
Total: 80 Characters
. . . . . .
1A 1B 1C 1D 1E 1F 20 21 22 23 24 25 26 27
. . . . . .
5A 5B 5C 5D 5E 5F 60 61 62 63 64 65 66 67
Total: 40 Characters x 2 Lines
Table 16.
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Dot-Matrix LCD Units
R
HD44780A
The contents of addresses (43), (47), (4B),
and (4F) may be destroyed.
The contents of address locations
23, 27, 63, and 67 may be lost
during the execution of the
display/cursor home instruction.
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LCD27-37
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